Fluid ejection devices, including, for example, inkjet printheads, have an orifice layer with nozzles or orifices through which fluid is ejected. Resistors are provided on a substrate. The resistors are in a firing chamber in a barrier layer below the orifice layer. The resistors are selectively energized, thereby heating fluid in the chamber, causing some of the fluid to be ejected from the nozzle. Changes in the orifice layer and or the barrier layer during manufacturing processes can result in imperfections in the surface of the orifice layer that affect the performance of the fluid ejection device.
Circuitry fabricated on a substrate structure using standard thin film techniques includes a conductive path for carrying electrical power for firing the resistors, an address bus, logic elements, and firing transistors. This circuitry is used to properly energize and operate the resistors. Capacitive coupling between the address bus and the fire line or power bus can generate noise and degrade performance.